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Java Program to Print array after it is right rotated K times

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Given an Array of size N and a values K, around which we need to right rotate the array. How to quickly print the right rotated array?
Examples : 
 

Input: Array[] = {1, 3, 5, 7, 9}, K = 2.
Output: 7 9 1 3 5
Explanation:
After 1st rotation - {9, 1, 3, 5, 7}
After 2nd rotation - {7, 9, 1, 3, 5}

Input: Array[] = {1, 2, 3, 4, 5}, K = 4.
Output: 2 3 4 5 1      

 

Approach:
 

  1. We will first take mod of K by N (K = K % N) because after every N rotations array will become the same as the initial array. 
     
  2. Now, we will iterate the array from i = 0 to i = N-1 and check, 
    • If i < K, Print rightmost Kth element (a[N + i -K]). Otherwise, 
       
    • Print array after ‘K’ elements (a[i – K]). 
       

Below is the implementation of the above approach. 
 

Java




// Java Implementation of Right Rotation 
// of an Array K number of times
import java.util.*;
import java.lang.*;
import java.io.*;
  
class Array_Rotation
{
  
// Function to rightRotate array
static void RightRotate(int a[], 
                        int n, int k)
{
      
    // If rotation is greater 
    // than size of array
    k=k%n;
  
    for(int i = 0; i < n; i++)
    {
        if(i<k)
        {
            // Printing rightmost 
            // kth elements
            System.out.print(a[n + i - k] 
                             + " ");
        }
        else
        {
            // Prints array after
            // 'k' elements
            System.out.print(a[i - k] 
                             + " ");
        }
    }
    System.out.println();
}
      
// Driver program
public static void main(String args[])
{
    int Array[] = {1, 2, 3, 4, 5};
    int N = Array.length;
  
    int K = 2;
    RightRotate(Array, N, K);
  
}
}
// This code is contributed by M Vamshi Krishna


Output: 

4 5 1 2 3

 

Time complexity : O(n) 
Auxiliary Space : O(1)
 

Please refer complete article on Print array after it is right rotated K times for more details!



Last Updated : 25 Jan, 2022
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